Interactions

Interactions with Drugs

Saw palmetto may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix®), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). Some batches of the discontinued combination herbal preparation PC-SPES®, which contains saw palmetto and seven other herbs, has been found to contain several medications including the "blood thinner" warfarin.

Saw palmetto should not be taken with drugs that affect the levels of male sex hormones (androgens), such as finasteride (Proscar®, Propecia®) or flutamide (Eulexin®). In theory, saw palmetto may interfere with birth control pills or hormone replacement therapy in women. Tinctures may contain high levels of alcohol and may cause nausea or vomiting when taken with metronidazole (Flagyl®) or disulfiram (Antabuse®).

Interactions with Herbs and Dietary Supplements

Based on at least two reports of serious bleeding, saw palmetto may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.

Because saw palmetto may have activity on the body's response to estrogen, the effects of other agents believed to have estrogen-like properties may be altered.